Typically, telecommunication systems used to provide broadband access to residential customers contain a residential gateway which consists of an xDSL (any type of digital subscriber line) modem combined with various local area networking (LAN) technologies to enable sharing the broadband access with other computers or devices within the residence. 802.11 wireless and home phone line networking (HPNA) are examples of LAN technologies. In addition, some telecommunication systems may provide a voice-over-internet-protocol (VOIP) feature to allow telephone calls via the broadband link.
Some systems may further include a femtocell base station capable of establishing relatively small wireless network coverage area. Additionally, the residential gateway may further include the features of an Internet Protocol Private Branch Exchange (IP-PBX) to make connections among the devices connected to the residential gateway. The IP-PBX handles voice signals under an Internet protocol and can exist as physical hardware or can carry out its functions virtually, performing the call-routing activities using a software system.
Typically, the residential gateway is located inside a house and connects a number of devices to one or more service provider's core networks. There are, however, several disadvantages with a conventional residential gateway having the features described above. In a conventional residential gateway, any transfer of a voice session between mobile cell phones or between Digital Enhanced Cordless Telecommunications (DECT) phones must be routed through the service provider's core network. This can add significant cost and delay and may be impossible if the service provider's network does not support the requested transfer function. Additionally call transfer between a mobile cell phone and a DECT phone does not exist. Furthermore, conventional residential gateways require each connection to be specifically formatted and do not support the transfer of data sessions, such as short message service (SMS) or instant message (IM) traffic.